Acrylamide polymers have a wide variety of applications. Examples include use as flocculants, agents for paper manufacturing, soil conditioners, agents for recovering petroleum, thickeners for drilling fluid, and polymer absorbers. An acrylamide polymer is required to have properties such that it has a very high molecular weight, it generates a small amount of water-insoluble matter when dissolved in water, and the like, in order to be put to use in such applications.
A variety of processes have been proposed as processes for obtaining such high molecular weight acrylamide polymer with good solubility. An example of such process is carried out by using a chain transfer agent that prevents polymers with abnormally high molecular weights from being generated or a substance that can prevent crosslinking, which occurs under dry conditions. However, the quality of acrylamide is presumed to significantly affect the quality of the acrylamide polymer. This can be deduced based on the fact that, for example, a variety of processes for producing acrylamide from which impurities such as acrolein or oxazole have been removed have been proposed (for example, JP Patent Publication (Kokai) Nos. 8-157439 A (1996) and 10-7638 A (1998)).
Up to the present, however, there has been no report concerning the influence of a saccharide on the properties of the acrylamide polymer.
In the past, acrylamide used to be produced from acrylonitrile with the use of reduced copper as a catalyst. Recently, a process in which a microbial enzyme is used instead of a copper catalyst has been developed and put to practical use. The process in which a microbial enzyme is used is very effective as an industrial production process since the reaction conditions are moderate, substantially no by-product is generated, and this process can be very simply carried out.
Acrylamide produced with the use of a microbial enzyme generates only small amounts of impurities. Thus, high-quality polyacrylamide that has a very high molecular weight and is free from insoluble impurities can be produced therefrom (JP Patent Publication (Kokai) No. 9-118704 A (1997)). Accordingly, such production process is a major process for producing acrylamide these days.